Recently, research for broadcasting multi-view videos through a Digital Television (DTV) has been conducted. To broadcast multi-view videos similar to actual videos seen with human eyes, the multi-view videos should be created and transmitted. Then, the multi-view videos should be received and reproduced by a display apparatus. However, since the multi-view videos have a large amount of data, it is difficult to receive the multi-view videos at the bandwidth of channels used in a current digital broadcasting system. Accordingly, research is being conducted on a technology for coding and decoding multi-view videos.
Multi-view Video Coding (MVC) is a technology which codes a plurality of videos acquired from a plurality of cameras having different views and a plurality of depth information videos corresponding to the plurality of videos, that is, multi-view videos. For an identical object, the plurality of cameras are disposed so as to be spaced from each other in accordance with predetermined rules in distance and direction. As a result, a high correlation exists between the respective videos having different views and composing the multi-view videos. When the high correlation between the respective videos is properly used, it is possible to remarkably improve the coding efficiency of the MVC. However, since lights reflected from the identical object may differ from each other depending on directions, the lights may be considered to maximize the coding efficiency.
The MVC of which the standardization is being actively conducted is based on H.264/MPEG part 10 Advanced Video Coding (hereafter, referred to as H.264/AVC), which is an existing international moving picture coding standard. In the MVC, the above-described characteristics of the multi-view video are considered to find a method for improving the coding efficiency. For example, a hierarchical B-pictures coding process, which is performed to support temporal scalability in Joint Scalable Video Coding (JSVC) defined in the H.264/AVC, is applied to intra-view prediction coding. Furthermore, the inter-view prediction coding is performed side by side with the intra-view prediction coding to improve the coding efficiency in the MVC. Accordingly, much research on reception and transmission of three-dimensional (3D) videos through the DTV broadcasting is being conducted by the associated groups which research 3D videos. Currently, the research is aiming at the transmission and reception of High Definition (HD) stereo videos. The HD stereo video refers to an interlaced video having a size of 1920×1080 or a progressive video having a size of 1024×720.
FIG. 1 is a block diagram explaining a conventional multi-view video coding/decoding system.
Referring to FIG. 1, the conventional multi-view video coding/decoding system includes a first video coding unit 101, a first video decoding unit 103, a first depth information video coding unit 105, a first depth information video decoding unit 107, a second video coding unit 109, a second video decoding unit 111, a second depth information video coding unit 113, and a second depth video information decoding unit 115.
First and second videos and first and second depth information videos are inputted to the first and second video coding units 101 and 109 and the first and second depth information video coding units 105 and 113, respectively. The first and second videos have a different view from each other, and the first and second depth information videos correspond to the first and second videos, respectively, and include depth information. In the conventional multi-view video coding/decoding system, two or more videos may be used, and the number of depth information videos may correspond to the number of videos. At this time, multi-view videos may be coded using videos having different views. That is, a high correlation exists between the multi-view videos. Therefore, when the first video is first coded, the second video coding unit 109 may code the second video by referring to the coded first video. The depth information video may be coded in the same manner.
The respective coded videos are inputted to the first and second video decoding units 103 and 111 and the first and second depth information video decoding units 107 and 115, and then decoded.
A two-dimensional (2D) video is a video obtained by decoding the coded first or second video, and a 3D video is a video obtained by decoding the coded first and second videos and the coded first depth information video. The first video may be a video having a reference view. A multi-view video is a video obtained by decoding the coded first and second videos and the coded first and second depth information videos.
That is, in the conventional multi-view video coding/decoding system, the coding and decoding of the multi-view video and the depth information video are performed independently.